// Container.cs - customizations to Gtk.Container
//
// Authors: Mike Kestner  <mkestner@ximian.com>
//
// Copyright (c) 2004 Novell, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 2 of the Lesser GNU General 
// Public License as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.

namespace Gtk {

	using System;
	using System.Collections;
	using System.Runtime.InteropServices;

	public partial class Container : IEnumerable {

		[DllImport("gtksharpglue-3")]
		static extern void gtksharp_container_child_get_property(IntPtr container, IntPtr child, IntPtr property, ref GLib.Value value);

		public GLib.Value ChildGetProperty(Gtk.Widget child, string property_name) {
			GLib.Value value = new GLib.Value();

			IntPtr native = GLib.Marshaller.StringToPtrGStrdup(property_name);
			gtksharp_container_child_get_property(Handle, child.Handle, native, ref value);
			GLib.Marshaller.Free(native);
			return value;
		}

		public IEnumerator GetEnumerator() {
			return Children.GetEnumerator();
		}

		class ChildAccumulator {
			public ArrayList Children = new ArrayList();

			public void Add(Gtk.Widget widget) {
				Children.Add(widget);
			}
		}

		public IEnumerable AllChildren {
			get {
				ChildAccumulator acc = new ChildAccumulator();
				Forall(new Gtk.Callback(acc.Add));
				return acc.Children;
			}
		}

		[DllImport(Global.GtkNativeDll, CallingConvention = CallingConvention.Cdecl)]
		static extern bool gtk_container_get_focus_chain(IntPtr raw, out IntPtr list_ptr);

		[DllImport(Global.GtkNativeDll, CallingConvention = CallingConvention.Cdecl)]
		static extern void gtk_container_set_focus_chain(IntPtr raw, IntPtr list_ptr);

		public Widget[] FocusChain {
			get {
				IntPtr list_ptr;
				bool success = gtk_container_get_focus_chain(Handle, out list_ptr);
				if (!success)
					return new Widget[0];

				GLib.List list = new GLib.List(list_ptr);
				Widget[] result = new Widget[list.Count];
				for (int i = 0; i < list.Count; i++)
					result[i] = list[i] as Widget;
				return result;
			}
			set {
				GLib.List list = new GLib.List(IntPtr.Zero);
				foreach (Widget val in value)
					list.Append(val.Handle);
				gtk_container_set_focus_chain(Handle, list.Handle);
			}

		}

		[DllImport("gtksharpglue-3")]
		static extern void gtksharp_container_base_forall(IntPtr handle, bool include_internals, IntPtr cb, IntPtr data);

		[DllImport("gtksharpglue-3")]
		static extern void gtksharp_container_override_forall(IntPtr gtype, ForallDelegate cb);

		[DllImport("gtksharpglue-3")]
		static extern void gtksharp_container_invoke_gtk_callback(IntPtr cb, IntPtr handle, IntPtr data);

		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		delegate void ForallDelegate(IntPtr container, bool include_internals, IntPtr cb, IntPtr data);

		static ForallDelegate ForallOldCallback;
		static ForallDelegate ForallCallback;

		public struct CallbackInvoker {
			IntPtr cb;
			IntPtr data;

			internal CallbackInvoker(IntPtr cb, IntPtr data) {
				this.cb = cb;
				this.data = data;
			}

			internal IntPtr Data {
				get {
					return data;
				}
			}

			internal IntPtr Callback {
				get {
					return cb;
				}
			}

			public void Invoke(Widget w) {
				gtksharp_container_invoke_gtk_callback(cb, w.Handle, data);
			}
		}

		static void ForallOld_cb(IntPtr container, bool include_internals, IntPtr cb, IntPtr data) {
			try {
				//GtkContainer's unmanaged dispose calls forall, but by that time the managed object is gone
				//so it couldn't do anything useful, and resurrecting it would cause a resurrection cycle.
				//In that case, just chain to the native base in case it can do something.
				Container obj = (Container)GLib.Object.TryGetObject(container);
				if (obj != null) {
					CallbackInvoker invoker = new CallbackInvoker(cb, data);
					obj.ForAll(include_internals, invoker);
				} else {
					gtksharp_container_base_forall(container, include_internals, cb, data);
				}
			} catch (Exception e) {
				GLib.ExceptionManager.RaiseUnhandledException(e, false);
			}
		}

		static void OverrideForallOld(GLib.GType gtype) {
			if (ForallOldCallback == null)
				ForallOldCallback = new ForallDelegate(ForallOld_cb);
			gtksharp_container_override_forall(gtype.Val, ForallOldCallback);
		}

		[Obsolete("Override the ForAll(bool,Gtk.Callback) method instead")]
		[GLib.DefaultSignalHandler(Type = typeof(Gtk.Container), ConnectionMethod = "OverrideForallOld")]
		protected virtual void ForAll(bool include_internals, CallbackInvoker invoker) {
			gtksharp_container_base_forall(Handle, include_internals, invoker.Callback, invoker.Data);
		}

		static void Forall_cb(IntPtr container, bool include_internals, IntPtr cb, IntPtr data) {
			try {
				//GtkContainer's unmanaged dispose calls forall, but by that time the managed object is gone
				//so it couldn't do anything useful, and resurrecting it would cause a resurrection cycle.
				//In that case, just chain to the native base in case it can do something.
				Container obj = (Container)GLib.Object.TryGetObject(container);
				if (obj != null) {
					CallbackInvoker invoker = new CallbackInvoker(cb, data);
					obj.ForAll(include_internals, new Gtk.Callback(invoker.Invoke));
				} else {
					gtksharp_container_base_forall(container, include_internals, cb, data);
				}
			} catch (Exception e) {
				GLib.ExceptionManager.RaiseUnhandledException(e, false);
			}
		}

		static void OverrideForall(GLib.GType gtype) {
			if (ForallCallback == null)
				ForallCallback = new ForallDelegate(Forall_cb);
			gtksharp_container_override_forall(gtype.Val, ForallCallback);
		}

		[GLib.DefaultSignalHandler(Type = typeof(Gtk.Container), ConnectionMethod = "OverrideForall")]
		protected virtual void ForAll(bool include_internals, Gtk.Callback callback) {
			CallbackInvoker invoker;
			try {
				invoker = (CallbackInvoker)callback.Target;
			} catch {
				throw new ApplicationException("ForAll can only be called as \"base.ForAll()\". Use Forall() or Foreach().");
			}
			gtksharp_container_base_forall(Handle, include_internals, invoker.Callback, invoker.Data);
		}

		// Compatibility code for old ChildType() virtual method
		static IntPtr ObsoleteChildType_cb(IntPtr raw) {
			try {
				Container obj = GLib.Object.GetObject(raw, false) as Container;
				GLib.GType gtype = obj.ChildType();
				return gtype.Val;
			} catch (Exception e) {
				GLib.ExceptionManager.RaiseUnhandledException(e, false);
			}

			return GLib.GType.Invalid.Val;
		}

		static ChildTypeNativeDelegate ObsoleteChildTypeVMCallback;

		static void OverrideObsoleteChildType(GLib.GType gtype) {
			if (ObsoleteChildTypeVMCallback == null)
				ObsoleteChildTypeVMCallback = new ChildTypeNativeDelegate(ObsoleteChildType_cb);
			OverrideChildType(gtype, ObsoleteChildTypeVMCallback); // -> autogenerated method
		}

		[Obsolete("Replaced by OnChildType for implementations and SupportedChildType for callers.")]
		[GLib.DefaultSignalHandler(Type = typeof(Gtk.Container), ConnectionMethod = "OverrideObsoleteChildType")]
		public virtual GLib.GType ChildType() {
			return InternalChildType(); // -> autogenerated method
		}

		public class ContainerChild {
			protected Container parent;
			protected Widget child;

			public ContainerChild(Container parent, Widget child) {
				this.parent = parent;
				this.child = child;
			}

			public Container Parent {
				get {
					return parent;
				}
			}

			public Widget Child {
				get {
					return child;
				}
			}
		}

		public virtual ContainerChild this[Widget w] {
			get {
				return new ContainerChild(this, w);
			}
		}
	}
}